Electric phonograph



May 19, 1931. A. A. THOMAS ELECTRIC PHONOGRAPH Filed Dec. 4, 1926 3 Sheets-Sheet l 5 INVENTOR y 9, 1931. A. A. THOMAS 1,806,374

ELECTRIC PHONOGRAPH Filed Dec. 4, 1926 3 Sheets-Sheet 2 INVENTOR May 19, 1931. A. A. THOMAS ELECTRIC PHONOGRAPH Filed Dec. 4, 192.6 5 Sheets-Sheet 5 INVENTOR Patented May 19, 1931 AIDOIJEFII A. THOMAS, OF NEW YORK, N. Y.

ELECTRIC PHONOGRAIH Application filed December 4, 1926.

My I invention rel-ates to electric phonographs, and its object is toprovide an iniproved instrument 1 of that type embodying various features of novelty,:as will later-be explained in detail. The main --purpose of my inventionisto produce an electric phonograph of the portable or table type, in which all the pa rts a're mounted in a carrying case of comparatively small dimensions, and yet which is capable of-giving a reproduction of great volumeequal to' that of large cabinet ph'onographs. I do not want to 'createthe impression, however, that this invention 1 is limited to portable phonographs,nfor it may obviously be installed in stationary: houselioldcabinets; Imerely want to emphasize the point that my invention contains :novel features 1 particularly applicable: to portable electric phonographs; i

One of the important features of my :in-

vention is a =loudspeakingrdiaphragm of suitable construction mounted inside the lid of the carrying case without interfering with the closingof the lid. The electromagnetic driv-ingunitfor the diaphragmisalsoniount- 'e don-the lid. The-diaphragm and its driving unit are preferably carried by-a frame which is secured as: a unitary attachment to the inside of tlielid. If the carrying case'is made rectangular, the diaphragm maybe elliptical or-"oVal, soas-t-o have maxiinum vibrating-surface'with-in the rectangular area of'the lid.

There is ample room in the rcase to house'the various electrical devices that go to :make .up the electric transmission system :between the reproducer and the driving unit. In a preferred embodiment of my invention as applied to portable phonographs, there is a A compartmentfor records below the motor chamber. The cover of this record compartment is automatically locked and u-nlockedby merely closing anclc'opening the lid.

=A further-feature immynew electricphonograph comprises 'means for automatically controlling the reproducer circuit by the Serial No. 152,525.

movements or positiono'f the lid. lVhenthe lid is closed,it operates a switch inside the case to openall battery CllCllltSfSO that no current can flow when the case is closed and carried about. lVhen the-machine is to be used and the lid thrown open,-the switch is automatically closed and the reproducing circuits are in operative condition. In a preferred form of my invention, the lid-controlled locking means for the record compartment also controls the battery switch.

The foregoing and other featuresand advantages of my invention will be fu'lly understood from a detailed description of the accompanying drawings, in which I have illustrated two constructionsof portableelectric phonographs as exemplifications of my invention. In these drawings- Fig. 1 represents a plan view of a phonograph constructed in accordance with my invention, the lid being shown open;

Fig. 2 is a front View of the construction shown in Fig. 1, a portion of-the carrying case being broken away to show certain parts inside;

Fig. 3 is a cross-section on line 3-3 of Fig. 1

Fig. 4 is a fragmentary detailed View showing how the driving unit is supported in-the frame that carries the diaphragm;

Figs. 5' and 6 show two forms of electric transmission systems between the electric reproducer and the loudspeaker diaphragm;

Fig. 7 is a plan view of a slightly modified construction Fig. 8 shows a front view of Fig. 7. Referring to the construction illustrated in Figs.'14,there is a suitable carrying case or cabinet indicated as a whole by C, which 'is so proportioned anddesignedas to house I compactly all the partsthat go to make up a complete electric phonograph. A lid 10 is hinged at 11 to the rear edge of the case, which may be made of wood, fiber, sheet'metal, or any other appropriate material. A collap's-" ible link connection 12, or other practical 'means, holds the lid in upright open pos1- tion. When the lid 10'is'closed, the case or cabinet G is a practically dust-proof box, which can be carried about like a small piece of hand-baggage. For this purposev the case is provided with a'handl-e 13, and the lid 10 is locked in closed position by any practical means, not necessary to show or describe.

On the inside of lid 10 is secured a loudspeaking diaphragm 14, which is preferably 7 (but not necessarily) in the shape of a cone Cone dia phragms, as they are usually called in the with acircular or elliptical base.

trade, are well known and are usually made of stiff paper or parchmenhbutthey may also be made of" light sheet metahcelluloid,

stiflened impervious cloth, and other practical materials. The diaphragm may also be made'flat, as ofthin corrugated paper or ,metal. Bymaking the'diaphragm 14 "of elliptical shape, it is possible to support a dial Screws or other fastening members 20vpass through lugs 19 into the lidfor rigidly securphragm of maximum. acoustic surface within the rectangular area of lid 10, as plainlysh'own in Fig. 2. In the broader aspect of my invention, any practical form and shape j of loudspeaking diaphragm may be secured tolthe inside of lid 10; Instead of mounting the diaphragm directly on the inside wall of the lid, I prefer to use asupp-orting frame15 having an'elliptical ring 16 to which the edge of the diaphragm is secured, as by means of a clamping ring 17 and screws or rivets 18.

The diaphragmld is held spaced from the inner faceof the lid by lugs 19 on frame 15'.

' ing the frame and all parts carried thereby to the inside of the lid. As seen in Fig. 3, the lugs ;19;hold the supporting ring 16 spaced from. the lid so that sound waves produced I back of the diaphragmwillreadily find their .way intothefree air. If desired, lid 10 may be so constructed as to act in the manner of a sounding board for augmenting the vibrations of diaphragm 14. It should be noted that the lid also serves to direct the sound waves forwardly toward the listener, thereby increasing the acoustic effect of the diaphragm. Instead of being fiat, as shown, the lid may be domed outwardly, or it may slightly bulge inwardly at the center. The lid 1-0 is preferably provided with a peripheral fiange-or extensionadapted to form a shallow sound chamber in which the cone diaphragm is mounted and which acts to amplify the reproduction, particularly if the lid is constructed likea sounding board, As seen or lid. In other words, the sound chamber or recess formed by the lid directs the waves forward to-mingle with and reinforce other sound waves of the diaphragm, whereby the final volume is increased andthe tone quality of thereproduction improved. .7

The frame 15 is provided with cross-arms 21, which unite at the center to form a cylindrical housing 22 for supporting an electromagnetic driving unit 23. Since driving units of this kind are Well known in the art,

I neednot show or. describe any-structural 2 details thereof. .-It is enough to say-that the vibratory armature of driving unit 23 is connectedto the center ofd-iaphragm 14: by a link 24, which is to be. considered as'diagrammatically representing any operative connection (whether mechanical or electromagnetic) betweenthediaphragm and the drivlingvmechanism, The unit 23 is rigidly secured'in support 22 in any practical way.

InFigs. 3:and;t,1.I have shown a spring bar "25 pivoted ion a central stud 26 projecting from "the casing of unit 23." The support 22 is provided at oneend with an inturnedannularfiange 27, and atthe other end with an annular groove 28 formed by an overlying shoulder 29, which is slotted at 30 to permit entry of the spring bar 25 into locking groove 28. When the spring bar is turned under shoulder 29, the casing of unit 23 is rigidly held against the i'nturned flange 27 and thus securely locked in position. This locking arrangement permits ready removal of the unit when desired by simply turning the bar 25 into line with-slots 30. 'The casing of unit 23 is provided with a pair of binding posts 31 for receiving conductors 32, which form part of an electric transmission system between the electric phonograph reproducer and the driving unit, as will later be explained ,in detail. The diaphragm 14' and driving unit 23 are mounted on frame 15 and adjusted for the bestpossible operation beforefthe frame is secured to the lid; r r v The carrying case or cabinet C is provided ;with a motorboard 33 on which is'mounted a'turntable 341 driven-by a motor 35, which may-be electrical or mechanical and of any practical construction. As phonograph motors, both electrical and mechanical, are well known in the art and are-sold. separately by 'manufacturers, I need not show or. describe any detailsof the, driving'motor 35. If a mechanical motor is used, a winding'crankis inserted through a hole- 36 inthe front wall of the case. On themotorboard 33-is mounted a vertically and horizontally movable arm 37 carrying at its outer end an; electric phonograph reproducer 38 adapted to receive a suitable stylus for playing .phonograph records. There'are several-types and makes of electric phonograph reproducers on the market, and so I need not show or" describe the structural' details of reproducers 38. It will be suflicient totrefer to the diagrams of Figs. 5 and 6,.where 38 represents a reproducer of the microphone type, and 38*"indic'ates areproducerof theelectroma-gnetic type, usually called apick-up. Briefly stated, reproducer 38 ofFi g; 5' comprises a disk 39 connected to 33 the stylus arm-and adapted to press against carbon granules 4O to=vary the resistancebetween the disk and afixed terminal plate 41 provided with one or more coils'44, which are properly connectedin circuit, as will later be explained. It will be understood from the preceding remarks that, when I refer to the part 38 as an electric reproducer, I mean any practical device capable of producing electric impulses in accordance with the vibrations of a record-playing stylus, whether on lateral-cut records or vertical-cut records. If the reproducer arm 37 is in the form of a tube, theconnecting leads of the reproducer may be concealed therein. To hold the reproducer arm 37 in rest position, I provide a suitable support 45 which holds the arm in fixed position when the machine is carried about. A simple construction of support 45 would be a pair of spring fingers adapted to grip thearm and hold it firmly clamped until released. This will be understood without additional illustration.

Below the motorboard 33 are two vertical partitions 46 which form a pair of lateral chambers 47 and 48-. In these two chambers are housed the various electrical parts, such as batteries, amplifying tubes, transformers, resistances, etc., that go to make up a suitable amplifying transmission system between the reproducer 38 and driving unit 23. The precise disposition of these electrical parts in chambers 47 and 48 may bevaried to obtain the most compact and convenient arrangement in any given instance. Merely by way of example I have roughly indicated in chamber 47 a pair of audio-frequency transformers 49 and 50 and a pair of amplifying vacuum tubes 51 and 52. In chamber 48'Ihave indicated batteries 53 and 54, which may be considered, respectively, the filament and plate batteries of the amplifying system. It goes without sayingthat these various electrical devices are properly supported in chambers 47 and 48, so that they will not be. dislodged or disturbed during transportation of the machine. I have not deemed it necessary to show any details of such supporting means, for these are well within the skill of the mechanic. The chambers 47 and48 are provided with covers: 55 hinged at 56, so as to open sideways. Each cover has a finger-piece 57 for easy manipulation, and thecover for chamber 47 also has ventilating holes 58. Suitable means are provided for holding the covers 55 against accidental opening when the machine is carried about. When the covers 55 are closed,

they: form part. oi the top board of the case, being in effect continuations of motorboard Referring toFig. 2, it will be seen that the motor chamber is closed atthe bottom by a horizontal partition 59, which extends between the upright partitions 46 and may convenientlybe secured thereto. Between the horizontal partition 59 and the bottom of the cabinet is formed a compartment. 60 adapted to receive a stack of phonograph records. Instead of putting the records di rectly in compartment 60, I prefer to pro vide a tray 61 adapted to slide in. and out of thetcompartment. The front of tray 61 is closed by a panel 62, which normally forms part of the outer cabinet wall. Aknob. 63 permits the tray to be easily pulled out. for access to the records. To the sides of the record tray 61 are secured two angle pieces 64 having each a hole 65 in alignment with a hole 66 in. the horizontal partition 59; In line with each pair of holes 65. and 66 is mounted a slidable latch-bar 0r locking bolt 67 arranged to project through an opening 68 in motorboard 33.. The Openings 66 and 68 act as supporting bearings for the latchbar, as maybe seen from F ig; 2. A coil spring 69 surrounds each latch-bar for normally forcing the same upwardly? A suitable stop 7 0 carried by the latch-bar limits the upward movement thereof under the action of spring 69. It is clear from Fig. 2 that, when the latch-bars 67 are pushed down against the. springs, the lower ends thereof pass through the holes 65 in the angle pieces 64 of record tray 61, as indicated by dotted lines 67,. This looks the record tray in closedposition. I have provided means for automatically sliding the bars or bolts 67 into locking position when the lid 10 is closed. In the present instance, the lid is provided on the inside with a pair of studs 71 arranged to engagetheheads of locking bars 67 and force the same inwardly when the lid is closed; In-this way,1th.e mere closing of lid 10 automatically locks the record tray 61 without any attention on the part of the user. When the lid is thrown open, the springs 69 push the bars 67 outwardly into releasing position. Although I have shown a pair of locking bars, one would be suflicient.

In order to prevent waste of battery current when the machine is not in condition for use, I provide a switch adapted tobe automatically opened when the lid 10 is closed. For convenience, I use one of the locking bars 67 for operating the switch. Referring to Fig. 2, there is a switch consisting of apair of contacts 72 mounted in fixed position in chamber 48, as by being secured to the inside wall of the front panel of the cabinet. The switch contacts 72 are-insulated and properly connected in circuit, as will presently be eX- plained in connection with the wiring diagrams of Figs.- iand6. .jThe. adjacent locking. bar 67 carries a lateralzconducting arm 73 arranged to extend into chamber 48 through a slot 74 in partition 46. VVhenthe lid .lOis opened and the bar 67 forced upwardly by spring 69, the conducting arm 73 connects the spring -contacts 72 and the bat 72' are preferably ofspring metal so as to.

make good contact with arm 7 3. Any other practical construction of switch may be employed.

' As heretofore stated, the electric reproducer- 38 may represent a device of the micro,-

phone .type, as indicated by reproducer 38 in Fig. '5, or it may represent a reproducer of the electromagnetic type, as indicated by repro dimer-38 in Fig. 6. With. a microphone reproducer, the transmission system for operating the loudspeaking diaphragm 14 is usually simpler than where an electromagnetic repromicrophone reproducer are connected in the ducer'is used. Two illustrative amplifying systems between'the reproducer and the diaphragm areindicated in Figs. 5 and 6', which will now'be described. 7

V In Fig.5 the contacts 39, 40 and 41of the circuit of a battery 7 5 of suitable voltage. A radio filament battery will usually answer the purpose. The switch contacts 72, previously mentioned,are included in the'batterycircuit. The connecting arm 7 3 is shown in full lines to' close the switch, and in dotted position to indicate the opening of the switch. A irh'eo stat 7 6 is preferably included in the battery circuit'to regulatethe volume of reproduction. The electric impulses produced by the vibratory movements of the stylus arrn are amplified by means. of a step up transformer 77, the primary ofwhich is connected in'battery circuit and the secondary in the circuit ofthe electromagnetic driving unit '23. ,If desired, a further amplification of the current impulses produced in the'battery circuit may be obtained by using additional transformers, or employing amplifying tubes. Ordinarily,

however, a single amplifying transformer will'be found suflicient in the case of a microphone. reproducer'gfl 1 InFig. 6 we have asomewhat more elaborate transmission system, utilizing a pair of amplifying tubes 51 and 52 and a pair of coupling transformers 49 and 50. 'The tubes 51 and52 are of usual construction, including a filament- 78, a grid 7 9, and a, plate 80. The three electrodesof tube 52 are marked 7 8,

c 7 9 and 80, so as to distinguish them from the corresponding electrodes of tube 51. A wire or otherconductor81 connects grid 79 with one end of coil or coils 44, therother' end of which isconnected'throughra wire 82 with one, side of filament7 8. Thetwo filaments 78 and78' are connectedin parallel with a battery 53, by means of conductors83, 84, 85 and 86. In thecommon connection 87 is included the switch 7 2 and a rheost'at 88. What has previouslybeen said about the controlling action of switch 7273, isfully applicableto thecircuit of; filament battery 53. I The plate electrode 80 ofjtube 51' is connected to one end of the primary coil-89 of'transformer 49, and the'other end of that coil isfconnectedby a conductor 90 to the positive terminal of the platebattery 54. A controlling rheostat; 91 f is preferably included .in the last mentioned connection. The negative terminal of battery 54 is connected by wire92 to the common lead 834-85 ofthe filament circuit. The grid electrode 79- of tube 52 is connected by wire 98 to one terminal of the secondary'coil 94 of transformer 49. The other terminal of secondary' coil 94 is connected'tooneside of filament 7 8' by wire 95. V The plate electrode 90? of tube 52 is connected .by wire96 to one end of the primary coil 97 oftransformer .50. The other endof primary. coil 97 is connected through conductor98. with the positive pole of battery 54. The secondary coil 99 of transformer 50 is connected totheelectromagnetic driving unit 23.

tween the gridv and filament of tube 51. The

potential-variations thusset up ingrid 7 9 cause amplified-current impulses in the circuitofprimary coil 89, andthese current impulses induce; corresponding' voltage variations in the grid circuit oftube 52., This gives us'a second stage of 'amplificatiom'so thatthe transformer 50*finally' transmits greatly'amplified current impulses to the driving unit 23. The 1 filament rheostat 88 and plate rheostat-91, are adjusted'to give the best acoustic results in each particular case. t The, audio-frequency amplifying system of Fig. 6 is in operative condition only when the circuit of filament battery 53 is closed by the switch arm'7 3. If this transmissionsystem is provided,;as I prefer,.wlith the automatic switch control described'in connection with 2, then the filament circuitsof amplifying'tubes 51 and 52 are closed only whenthe lid 10 is open and are" automatically broken when the lid is closed.- Nof switch for the plate battery 54 is required,because the plate circuitsare not closed unless the filaments are heated to provide an electronic conducting path from-plate to filament. Consequently, when the filament circuit or circuits are broken, the plate battery circuit isa-utomatically interrupted.

Iwish to make it clear that the amplifying systems of Figs. 5 and 6. are not to be considered as limitations of my invention, but

merely as illustrative of .any practical means 1 In the modification of Figs. 7 and 8, the

longer sides :of lid 10 extendupwardly when the lid is opened, and'the diaphragm 14 is therefore arranged with its major axis vertical. The electrical' devices in this instance are housed in a chamberlOO arranged back of the-turntable 'andclosedlby a hinged cover 101. The chamber 100 may have a transverse partition 102'to provide a shallow space 103 adapted to house the crank for winding. the springmotor of the machine; If an electric motor isused, the space 103 maybe dispensed with or otherwise utilized. The dotted out lines appearing in chamber l00 of Fig. 7 indicate that-the battery 75 and transformer7 7 are suitably mounted within the chamber. Except for the differences noted, the construc tionof Figs. 7 and 8 is identical with that of Figs. 1- and 2, so that the detailed description of the last-mentioned. figures should be regarded as applicableto Figs. 7 and 8 withoutthe need of repetition. For convenience, I have numbered-corresponding parts of these two. constructions with the same reference characters. Althoughthe carryingcase in Figs. 7 and .8 is'shown as being. practically of the same size as that of Figs. 1 and 2, a construction like that ofFigs. 7 and Simay. be embodied in a case or.cabinetconsiderably smaller than that required forthe construction of Figs; 1 and 2. i V

The amplifying connections between the stylus arm of. electric reproducer 38 and the driving unit 23 ofdiaphragm 14 are'such that the volume ofreproduction can be made equal to, and indeed greater than, the volume obtainable from large cabinet phonographs containing amplifying horns; By mounting the loudspeakingdiaphragm 1 1 on the inside of the lid, the diaphragm is in the best position for reproduction, because the lid is upright when the machine is used and there fore the sound is thrown forwardly.- The lid 10 acts not only as a sound-directingwall,

but also as a soundingboard to amplify or augment the waves produced by the diaphragm. Itis thus possible, under myinvention, to construct an electric phonograph ofsuch compactness and small weight that it may. easily be carried about and stored in a smallspace, and yet capable of givingfa reproduction comparable in volume and quality'with that ofhigh-priced cabinet phono graphs.

It need hardly be mentioned thattheconstruction and mounting of diaphragm 14; are

such as to permit closing of the lid when the reproducer arm 37 is supported in idle or rest position, as shown in dotted lines in Fig. 1 and rin full lines in Fig. 7. The electrical parts of the transmission system are easily accessible by simply lifting the covers and 101, so that batteries may be replaced without trouble. The record compartment enables the user to provide himself with the desired music when he takes the phonograph with him on a trip. My new portable phonograph is especially useful in city apartments where rooms are small and space scarce. The phonographmay be placed on a table or chair for playing, and when-not in use it may be hidden away inacloset or other placewhere it will not be in the'way.

Although I have described certain specific constructions and circuit arrangements, I- want it understood that I have done so merely by way of example andnot as a. limitation of my invention. Various changes and modifications will doubtless occur to those skilled in the art, Without departing from the scope of the invention as defined in the following claims.

I' claim as my invention:

1. An electricphonograph comprising'a substantially fiat carrying case of rectangular shape,said case having. a pivoted lid and a top board provided with a turntable, the

shallow space between saidtopboard and the bottom of the case comprising at least two chambers arranged side byside, one of said chambers containing driving mechanism for the turntable and the other chamber containingelectric devices adapted to form a system for transmitting electric impulses, an electric reproducer mounted on said topboard and operatively connected with said devices, a loudspeaking diaphragm secured to the inside of said lid and spaced therefrom, said diaphragm and reproducer being so arranged as to permit closing of the lid, and'an electromagnetic driving unit: carried by. said lid for. vibrating said diaphragm, said unit being operatively connected with said devices.

2. An electric phonograph comprising a case of substantially rectangular shape and having a hingedlid at the'top, an elliptical diaphragm mounted on the inside ofsaid lidand open on both sides to the outer air when the lid is open, an electromagnetic unit also tame by isaidilid for I operating said diaphragm,': the major axis of said elliptical diaphragmbeing in the direction of the greater l'ength of said lid, whereby a diaphragm of maximum perimeter and acoustic area is supported within the rectangular spacejof the lid, an electricreproducer op erativ'elymountedlon the top board of said 3 case, said diaphragm and reproducer being 1' so arranged as to permit-closing of; the lid,

and electric mechanism for transmitting the vibrations 'of said re'producer to said driving unit.

7 3. A 'portable electric phonograph comprising a substantially flat carrying case having a pivoted lid and a'topboard, there being a shallow space between said topboard and the bottom of the case, a casting having an' annular rim and integral lugs projecting outwa-rdly therefrompfastening devices engagingsaid lugs to secure said frame" rigidly to the inner wall of saidflid,a loudspeaking diaphragm fastenedt'o said rim,,integral arms on said casting terminating in a head,

arrelectromagneticunit mounted in said head for operating said diaphragm, sa1d lugs holding said rim and diaphragm spaced from the supporting wall, an electric" reproducer V mountedon saldtopboard, and electric mechanism in said shallow space for transmitting the vibrations of saidzreproducer to said driv-' ing'unit'. t

' A -e t c phm ah p i substantiallyrectangular case, ahinged lid.

forming the jtop of said case, a top-board fixed in"the"bodyjof'said case, a :partition arranged below {said topboard sub stantially parallel" therewith to provide an upper chamber and a lower chamber, said upper chamber containlng az motor fordrivin'g the turntable, 'a movable; panel for. said" lower chamber which is adapted to receive records, said panel when closed form-. ing part of the outer structure or said case, 7 an 5 electric reproducer .operatively mounted on said topboard, ,a 'loudspeaking diaphragm. mounted on theinsi-de' ofsaid lid withoutimterfe'ring withthe closing thereof, an}electr,omag'netic unit also carried' by' said lid for op'eratingfsaid diaphragm, electric devices for transmitting the electric impulses oi'said reproducer to said driving unit, a locking member fors'aid movable panel, and means on said lid for? automatically actuating said memberfto lock" said panel when the lid is closed, said member automatically unlocking thelpanel when :the' lid is raised.

v 5. In an a cabinet h.av-'

electric phonograph,

, ing a lii d hinged at the top, electric reproducingme'chanismin saidcabinet, said' mechanism including an"electriclcirc-uit, a switch forssaid c1rcu t',1sa1d swltchlncludlng a vertically amovable rmem'ber which normally tendsto elose the circuit, and a projection on said 11d" tordepressing said member to open said .switchwhen lid is closed, said member automatically closing said switch when the lid is raised." I 6. In an electric phonograph, a case having ahinged lid and a compartment provided with a movable cover which normally forms part of the outer case structure, a movable locking member for said cover, means on said lid for moving said member into locking position when thelid is closed, said member automatically moving into unlocking posi;

tion when the lid'is opened, electric reprof ducingmechanism in said case, and a-switch included in said mechanism and controlled by said member.

'7. A portable electric phonograph "com prising a substantiallyflat rectangular carrying case having a hinged lid at the top, a horizontaltop board inthe body of said case, a horizontal partition between said top board and the bottom of said case to provide'an upper chamber for the motor and a lower shallow chamber adapted to'receive records,

said case having a'third chamber-arranged.

alongside said lower and upper chambers to house electric devices adapted to transmit electric impulses, an electric reproducer mounted on said top board, a loudspeaking diaphragm and its electromagnetic driving unit supported in said lid, and means for operatively connecting" said rep-roducer and f ClIlVlIlgllIlltlIl circuit wlth sald dev ces, sald diaphragm and reproducer permitting closure of the lid.

'8." An electric phonograph comprising a' cabinet having a top board'and' a hinged lid at the top, meansfor holding said lid raised in openposition, a loudspeakingdiaphragm;

mounted onthe inside of said lid, an elecarranged to form a'continuation of said top board, and anelec'tric reproduceroperatively mounted on "the top" boardand electrically connected with said system, said diaphragm and reproducer being soarrangedjas to per-'" mit'closing of the lid. 1 V V K 9. An electric phonograph comprising a case of substantially. flat rectangular shape, f

said case includinga hinged lid ,at the top adapted to be heldin raised open position,

vertical partitions"arranged in the body of "saidcaseto dividethesame into a central compartment for: the motor f and two side compartments for electrical devices adapted to form a transmission system for electric impulses, a" motor board covering the central j ,cdmpartment, a movable closure for each side compartment, said closures forming a connsoegem tinuation of said motor board, an electric reproducer operatively mounted on the motor board and electrically connected with said system, a loudspeaking diaphragm mounted on the inside of said lid without interfering with the closing thereof, and an electromagnetic driving unit also carried by said lid for operating said diaphragm, said lid when raised holding the diaphragm in substantially upright position open to the free air.

10. An electric phonograph comprising a case of substantially rectangular shape, said case including a hinged lid at the top provided with means to hold it in raised open position, vertical partitions arranged in the body of said case to divide the same into a central compartment and two side compartments, a horizontal partition in said central compartment to divide the same into an upper chamber and a lower chamber, a movable panel for said lower chamber which is adapted to receive records, said panel when closed forming part of the outer structure of said case, a motor board fixed in the upper part of said case to cover said upper chamber which contains a motor for driving the turntable, electric devices in said side compartments adapted to form a transmission system for electric impulses, a top cover for each side compartment, said side covers forming in effect continuations of said motor board to completely close the body of said case at the top, an electric reproducer operatively mounted on the motor board and electrically connected with said system, a loudspeaking diaphragm mounted on the inside of said top lid without interfering with the closing thereof, and an electromagnetic driving unit also carried by'said lid for operating said diaphragm, said lid when raised holding the diaphragm in substantially upright position open to the free air.

11. An electric phonograph comprising a case of substantially rectangular shape, said case including a hinged lid at the top provided with means to hold it in raised open position, vertical partitions arranged inthe body of said case to divide the same into a central compartment and two side compartments, a horizontal partition in said central compartment to divide the same into an upper chamber and a lower chamber, a movable panel for said lower chamber which is adapted to receive records, said panel when closed forming part of the outer structure of said case, a motor board fixed in the upper part of said case to cover said upper chamber which contains a motor for driving the turntable, electric devices in said side compartments adapted to form a transmission system for electric impulses, a top cover for each side compartment, said side covers forming in effect continuations of said motor board to completely close the body of said case at the top, an electric reproducer operatively thereof; an electromagnetic driving unit also i carried by saidlid for operating said diaphragm,sa1d llCl when raised holdlng the chaphragm in substantially upright position open to the free air, a locking device for said movable panel, means on said lid for automatically actuating said-device to lock said panelwhen thelid is closed, and a switch in said system automatically opened by said device when the latter is moved into locking position.

12. An electric phonograph comprising a cabinet having a pivoted lid and a topboard, said lid being provided with a peripheral flange which forms a shallow chamber, a casting having an annular rim and integral lugs projecting outwardly therefrom, fastening devices engaging said lugs to secure said frame rigidly to the inner wall of said lid whereby said rim and lugs are mounted in said chamber, a loudspeaking diaphragm fastened to said rim, integral arms on said casting terminating in a head, an electromagnetic unit mounted in said head for operating said diaphragm, said lugs holding said rim and diaphragm spaced from the supporting Wall so that the open shallow chamber formed by the flanged lid acts to reflect sound forwardly and thereby amplifies the reproduction, an electric reproducer mounted on said topboard, and electric mechanism for transmitting the vibrations of said reproducer to said driving unit.

13. An electric phonograph comprising a cabinet provided with elongated sound board having a peripheral extension to form a sound chamber, an elliptical diaphragm mounted on said boardand spaced therefrom, the major axis of said diaphragm being in the direction of the greater length of said board so that a diaphragm of maximum perimeter and acoustic area is supported in said chamber, and electric reproducer means for operating said diaphragm, said chamber amplifying the reproduction of the diaphragm.

14. In an electric phonograph, a cabinet provided with electric reproducing mechanism, a switch in said cabinet for controlling a circuit of said mechanism, said switch including a spring-pressed movable member normally projecting out of the cabinet to close said circuit, and a hinged closure on said cabinet adapted when closed to engage said member and move it inwardly into circuitbreaking position, said closure when opened moving out of engagement with said switch member which is thereby released and auto matically actuated into circuit-closing position.

15. In an electric phonograph, a cabinet provided with electric reproducing mechanism, 1a switch. in said cabinet for controL ling acircuitof said mechanism, said switch circuit-closing including a spring-pressed plunger normal- 1y projecting out of the cabinet to close Send circuit, and a hinged closure on said cabinet adapted when closed to push said plunger inwardly into circuit-breaking position, said closure when opened moving out of engage ment with said plunger which is thereby released and thrown by the spring'into normal position, I

ADOLPH A. THOMAS. 

